| |
Abstract:
Seeing a picture of an object will activate its concept
representation, some prephonological and phonological word
representations but hardly any orthographic representation of the
object name. However, if the picture is followed by the written
name of the depicted object the orthographic representation should
be activated, too. We compared the ERPs evoked by object names
either preceded by the picture of the object or by the object name
itself to capture the ERP response of word form activation. 15
students judged the identity of picture-name, name- name,
name-picture, and picture-picture pairs while the EEG was recorded
from 124 eletrodes. Minimum-norm current source density estimates
were computed for selected time epochs of the potential difference
ERP(name primed by picture) - ERP(name primed by name) and their
reliability was determined with a permutation test. Nine out of 15
subjects showed a component between 200 and 240 ms which could be
explained by either an unilateral or a bilateral current source in
the gyrus angularis, i.e. an area which has been delineated as
critical for word form processing by both lesion and PET studies.
In contrast, the potential difference ERP(picture primed by name) -
ERP(picture primed by picture) was dominated around 300 ms by a
component whose bilateral source was located in the visual
projection areas.
|
